1. Field of the Invention
The present invention relates to a winding machine and method particularly suitable for winding thick wire. This application is based on Patent application No. Hei 9-177427 filed in Japan, the contents of which are incorporated herein by reference.
2. Description of the Related Art
FIGS. 6 and 7 show an example of a conventional winding machine. In the winding machine, reference symbol W indicates a work piece (i.e., stator), reference symbols P' indicate winding sections (i.e., magnetic poles), reference symbols T' indicate wire fixing sections (i.e., terminals), reference symbol L indicates a wire (i.e., lead wire), reference symbol K' indicates a base, reference numeral 1 indicates the winding machine, reference numeral 2 indicates a nozzle, reference numeral 3 indicates driving means, reference numeral 4 indicates direction switching means, reference numeral 5 indicates winding position setting means, reference numeral 6 indicates wire cutting means (i.e., a wire cutter), and reference numeral 7 indicates a temporary tying pin.
Work W has, for example, plural magnetic poles P' projecting into the center, and has terminals T', disposed on its upper surface, to which wire L is connected, as shown in FIG. 6.
On base K' of the winding machine 1, nozzle 2 which is movable while pulling out wire L; driving means 3 for driving the nozzle 2; direction switching means 4 for making the direction of nozzle 2 switchable; and winding position setting means 5 for determining a position of winding section P' around which the wire L is wound are arranged. Additionally, nozzle 2 is moved in a manner such that it winds the wire W around winding section P', and the wire L is fixed to wire fixing section T' when winding is completed.
The driving means 3 consists of three-directional driving sections 31', 32' and 33', that is, cross-direction driving section 31', longitudinal-direction driving section 32', and vertical-direction driving section 33', combined with each other.
These driving sections 31', 32', and 33' have approximately the same driving mechanism along each driving direction X, Y, and Z.
The vertical-direction driving section 33' comprises vertical-direction guide 33A' arranged along driving direction Z, vertical-direction rotational shaft 33B' arranged in parallel with the vertical-direction guide 33A' and possessing male screw B on its surface, vertical-direction moving section 33C', combined with the vertical-direction rotational shaft 33B' via a ball screw, being movable along vertical-direction guide 33A', vertical-direction connective section 33D' connected with vertical-direction moving section 33C', and vertical-direction drive source 33E' for rotationally driving vertical-direction rotational shaft 33B'.
The vertical-direction rotational shaft 33B' is connected with vertical-direction drive source 33E' via universal joint 33F'. The moving range in driving direction Z of the vertical-direction moving section 33C' is determined according to the range of male screw B arranged on vertical-direction rotational shaft 33B'.
The cross-direction and longitudinal-direction driving sections 31' and 32', having structures similar to vertical-direction driving section 33', are respectively arranged along driving directions X and Y, as shown in FIG. 6. The cross-direction driving section 31' is fixed on base K and comprises (cross-direction) driving source 31E'. The longitudinal-direction driving section 32' is disposed such that the section 32' is movable via cross-direction connective section 31D' in the cross direction with respect to cross-direction driving section 31'. The longitudinal-direction driving section 32' comprises (longitudinal-direction) driving source 32E', and the vertical-direction driving section 33' is disposed such that the section 33' is movable via longitudinal-direction connective section 32D' in the longitudinal direction with respect to longitudinal-direction driving section 32'.
In vertical-direction driving section 33', vertical-direction connective section 33D' is horizontally projected in front of vertical-direction rotational shaft 33B'. Nozzle 2 is provided in vertical-direction driving section 33' via vertical-direction moving section 33C' coupled with vertical-direction rotational shaft 33B' and via vertical-direction connective section 33D', where nozzle 2 can move in the vertical direction with respect to vertical-direction driving section 33'.
Direction switching means 4 is arranged at vertical-direction connective section 33D', as shown in FIGS. 6 and 7, by which the direction of nozzle 2 can be switched between a vertical direction such as downward direction U and a direction perpendicular to the downward direction U, such as rear direction F. The direction switching means 4 comprises nozzle holder 41 extending downward from the head side of vertical-direction connective section 33D'; nozzle rotating section 42 rotatably attached to the nozzle holder 41; and direction setting section 43 for determining the direction of the nozzle rotating section 42.
As shown in FIG. 7, at the base-end side of nozzle holder 41, guide roller 41A for introducing wire L to nozzle 2 is provided. The nozzle rotating section 42 is rotatably attached to the lower end of nozzle holder 41 via shaft 41B, and nozzle 2 is provided to nozzle rotating section 42. The direction setting section 43 comprises crank 44, connected to nozzle rotating section 42, for rotationally driving nozzle rotating section 42 when the section 43 moves in the direction of its length, and crank driver 45 for driving the crank 44 in the vertical direction. The crank 44 comprises lower crank 44A connected with nozzle rotating section 42 via axis 42A, and upper crank 44B connected with crank driver 45. The lower and upper cranks 44A and 44B are connected with each other via joint 46 for enabling nozzle rotating section 42 to rotate when crank 44 is driven.
Winding position setting means 5 is disposed on base K', on which stator W is fixed. The setting means 5 is connected with a servo motor or the like, and has an index mechanism for rotating stator W by the pitch of (or distance between) magnetic poles P' when winding of each magnetic pole is completed.
Wire cutting means (wire cutter) 6 is disposed at a position on base K', suitable for cutting wire L, and comprises cutter 61' for cutting wire L; moving section 65 to which the cutter 61' is provided; motion rail 62' for defining the (moving) position of the moving section 65; a driving source (not shown), provided inside the motion rail 62', for moving cutter 61' along motion rail 62' by driving moving section 65; cutting operating section 63' for making cutter 61' perform a cutting operation during and in cooperation with the driving operation along motion rail 62' by the driving source; and supporter 64, fixed to base K', for supporting the above parts of wire cutter 6 on base K'.
Temporary tying pin 7 is disposed on base K', near the winding position setting means 5 and wire cutter 6.
In winding operations of the above winding machine 1, by using driving means 3, wire L is wound around winding section P' by moving nozzle 2 around winding section P', and then wire L is tied to terminal T'.
When wire L is tied to terminal T', nozzle 2 is moved around terminal T', as shown in FIG. 8A. In this operation, as shown in FIG. 8B, nozzle 2 is rotationally moved in a manner such that the position of nozzle 2 is always in parallel with terminal T' and has a cylindrical locus around terminal T'. Also in this tying operation of wire L, in which nozzle 2 is moved around terminal T', the angle between the direction of wire L pulled out from the head of nozzle 2 and the direction of the axis of nozzle 2 is .theta., as shown in FIG. 8A.
In the above-mentioned winding machine 1, the following problems have occurred.
(1) It is necessary to position nozzle 2 close to terminal T' in order to ensure a precise winding position of wire L. However, on the assumption that the height of nozzle 2 is fixed, the above angle .theta. increases as nozzle 2 comes close to terminal T' to which wire L is tied. In order to reduce this angle .theta. in the tying operation, the head of nozzle 2 may be positioned further away in a slantwise and upward direction from the position on terminal T' at which wire L is tied. However, in such a situation, the position for tying wire L is too distant from the position of the head of nozzle 2. Therefore, it is difficult to precisely arrange positional relationships between each element in the tying operation of wire L around terminal T'. PA0 (2) If the tying operation to terminal T' is performed with a large .theta.0 so as to precisely determine a position for winding, wire L is heavily bent near the opening area of the nozzle head. In this case, the frictional force between nozzle 2 and wire L is increased, and thus great tension is exerted on wire L. Accordingly, if a wire having a small diameter (i.e., a thin wire: approximately .phi.0.02 mm) is used, the wire may break due to the above tension during the tying operation. On the other hand, if a wire having a large diameter (i.e., a thick wire: .phi.1.2-1.3 mm) is used, then tension increases by approximately twice as much as the above-mentioned tension; thus, terminal T' may be deformed as shown in FIG. 8C. PA0 (3) If a path or route from winding section P' around which wire L is wound to terminal T' to which wire L is tied must be complicatedly defined, or if the position of terminal T' is away from the direction of nozzle 2, which can be switched between plural directions such as horizontal and downward directions by direction switching means 4, the tying operation using the above winding machine 1 is impossible. PA0 (1) To perform winding and tying operations suitable for each shape of various kinds of works. PA0 (2) To define any locus from a winding section to a terminal. PA0 (3) To make wire tension fixed. PA0 (4) To improve accuracy of the winding position. PA0 (5) To prevent breaking of wire and deformation of the wire fixing section. PA0 (6) To perform winding operations suitable for each diameter of various kinds of wires. PA0 (1) By setting the direction of the nozzle by using the direction setting means, it is possible to perform a tying operation to a terminal, which is suitable for each shape of various kinds of work pieces. The most suitable driving of the nozzle can be performed by the driving means and the direction setting means, by which it is possible to perform a winding operation suitable for each shape of various kinds of work pieces. PA0 (2) The nozzle can be driven in three axes by the driving means, and the direction of the nozzle can be set by the direction setting means. Therefore, a locus from the winding section to the terminal can be arbitrarily defined. PA0 (3) Tension imposed on the wire at the head of the nozzle can be reduced by setting the direction of the nozzle by direction setting means, and tension at the opening of the base end of the nozzle can be reduced using the guide rollers, by which the wire tension during the winding and at the time of ending the winding can be fixed. PA0 (4) The relative position of the nozzle with respect to the winding section can be set by the driving means which can perform a three-axis driving operation and by the direction setting means. Therefore, accuracy of the position of the winding can be improved. In addition, the head of the nozzle may intersect an extension line of the direction-setting rotational shaft, and thereby the head of the nozzle is movable with respect to the wire fixing section in an integral moving form with the direction-setting rotational shaft. Therefore, it is possible to easily set the position of the nozzle during winding. PA0 (5) By setting the tension of the wire to be fixed by using the direction setting means and the guide rollers, it is possible to prevent breaking of a thin wire and deformation of the wire fixing section when a thick wire is used. PA0 (6) According to the above advantages, winding operations suitable for each diameter of various kinds of wires can be realized.